package com.chen.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

@RestController
public class FileController {
    //    @RequestParam("file") 将name=file控件得到的文件封装成CommonsMultipartFile对象
//    批量上传CommonsMultipartFile则为数组即可
    @RequestMapping("/upload")
    public String upload(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
//        获取文件名
        String uploadFileName = file.getOriginalFilename();
//        如果文件名为空
        if ("".equals(uploadFileName)){
            return "redirect:/index.jsp";
        }
        System.out.println("上传文件名"+uploadFileName);
//        上传路径保存位置
        String path = request.getServletContext().getRealPath("/upload");
//        如果路径不存在，创建一个
        File realPath = new File(path);
        if (!realPath.exists()) {
            realPath.mkdir();
        }
        System.out.println("上传文件保存地址" + realPath);

        InputStream is = file.getInputStream();//文件输入流
        OutputStream os = new FileOutputStream(new File(realPath, uploadFileName));//文件输出流

//        读取写出
        int len = 0;
        byte[] buffer = new byte[1024];
        while ((len = is.read(buffer)) != -1) {
            os.write(buffer, 0, len);
            os.flush();
        }
        os.close();
        is.close();

        return "redirect:/index.jsp";
    }
    //    采用file.Transto 来保存上传的文件
    @RequestMapping("/upload2")
    public  String upload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
//        上传路径保存位置
        String path = request.getServletContext().getRealPath("/upload");
//        如果路径不存在，创建一个
        File realPath = new File(path);
        if (!realPath.exists()) {
            realPath.mkdir();
        }
//        上传文件地址
        System.out.println("上传文件保存地址" + realPath);
//       通过CommonsMultipartFile的方法直接写文件
        file.transferTo(new File(realPath+"/"+file.getOriginalFilename()));
        return "redirect:/index.jsp";
    }

    //    图片下载
    @RequestMapping("/download")
    public String download(HttpServletResponse response, HttpServletRequest request) throws Exception {
//        需要下载的图片地址
        String path=request.getServletContext().getRealPath("/upload");
        String fileName="1.png";
//       设置response 响应头
        response.reset();//设置页面不缓存，清空buffer
        response.setCharacterEncoding("utf-8");//字符编码
        response.setContentType("multipart/form-data");
//        设置response响应头
        response.setHeader("Content-Disposition","attachment;fileName="+
                URLEncoder.encode(fileName,"UTF-8"));
        File file=new File(path,fileName);
//       读取文件----输入流
        InputStream input=new FileInputStream(file);
//        写出文件----输出流
        OutputStream out=response.getOutputStream();

        byte[] buffer=new byte[1024];
        int index=0;
//       执行写出操作
        while ((index=input.read(buffer))!=-1){
            out.write(buffer,0,index);
            out.flush();
        }
        out.close();
        input.close();
        return "ok";

    }
}
